Pressure Relief Vertical Mount 3510-4X4 Commercial 12 & 14" * Mill

12 & 14" * Mill finish

Individually welded 14 guage diffusion bars

Building materials rated 2 hours or less

Standard Features * 3550 - Vertical mount * 3560 - Horizontal mount air up * 3570 - Horizontal mount air down * 3580 - Round sizes available 5" to 24" * All non-motorized backdraft dampers * Dampers are opened by air pressure differential and closed by gravity * 16 gauge channel frame with 26 gauge galvanized blades * Out-of-airstream linkage * Blades are vee stiffened 26 gauge for strength and stability * Square steel pivot pins * Nylon bushings * Single blades on 10" width or less * Adjustable counter balance to adjust various opening pressures * Galvanized finish h3

Pressure Relief Vertical Mount 3510-4X4 Commercial 12 & 14" * Millh3. Standard Features * 3510 Vertical mount * 3520 Horizontal mount air up * 3530 Horizontal mount air down * Designed to open with negative or positive pressures for intake or exhaust air * Felt edge blades to hold noise to a minimum * Aluminum construction * Blade to blade linkage * 1 4" pivot pins in nylon busings * Maximum size 24 x 24 * Mill finish h3. Options * Sleeve variations * Mounting flange * Adjustable counter balance to adjust various